I am driving for Doordash - a few delivery service similar to GrubHub or Uber Eats. Can I deduct the mileage I drive on deliveries in 2018?
If you are a W-2 employee, then no, not one penny of unreimbursed employee expenses can be deducted. If you are a 1099-MISC employee then you are self-employed for that income, and it's deductible as a business expenses on SCH C.